1. Field of the Invention
The present invention relates to an original cover closer suitable for use in office equipment such as a copying machine, a printer, a facsimile machine, a scanner, and so on, and office equipment including the original cover closer.
2. Description of the Related Art
The main body of office equipment such as a copying machine, a printer, a facsimile machine, a scanner, and so on has an original cover attached to be rotatable to the top surface of the main body via an original cover closer. The original cover closer is a kind of hinge mechanism which can axially support the original cover to be rotatable around a hinge pin to thereby position the original cover on a contact glass on the top surface of the main body and expose the contact glass. An original can be set on the contact glass by rotating the original cover (moving it upward) to expose (open) the contact glass, mounting the original on the surface of the contact glass, then rotating the original cover in the reverse direction (moving it downward) to bring the original into intimate contact with the top of the contact glass by the original cover.
Such original cover closers include a well-known one in which a lifting member can be provided to bring the original into intimate contact with the contact glass irrespective of the thickness of the original and the urging force of a resilient means can be used to rotate the original cover without making a person feel the weight of the original cover itself (see, for example, the later-described Patent Document). Usually, two original cover closers are provided to support the original cover on the main body of the office equipment to be opened and closed. Use of these two original covers each including the resilient means leads to increased cost as a whole. Hence, in the case where a heavy article such as an original automatic feeder is attached to the original cover to cause the center of gravity of the original cover shift either to the right or to the left, an original cover closer including a resilient means has been used on the side to which the center of gravity has been shifted and an original cover closer including no resilient means has been used on the side opposite to the side to which the center of gravity has been shifted, whereby a significant reduction in cost as a whole has been achieved. The Patent Document is Japanese Patent Application Laid-open No. H11-95339.
Incidentally, in the above-described well-known original cover closer, a second original cover closer supporting the original cover on the side opposite to the side to which the center of gravity is shifted is provided with a lifting member to be able to bring the original into intimate contact with the contact glass irrespective of the thickness of the original, but has a complicated structure. More specifically, the second original cover closer includes a mounting member mounted on a main body of office equipment; a supporting member axially supported to be rotatable on the mounting member; a lifting member overlapping the supporting member, axially supported on a free end of the supporting member, and mounted on the original cover; and a tension coil spring provided between the supporting member and the lifting member, for urging the lifting member in a direction in which the lifting member overlaps the supporting member. One end of the tension coil spring is mounted on the supporting member and the other end thereof is mounted on the lifting member, the supporting member is provided with a guide pin, and the lifting member is provided with a guide groove in an arc-shape into which the guide pin in intruded, so as to urge the lifting member in a direction in which the lifting member overlaps the supporting member, bringing about a problem of the structure being complicated. Another problem is that since the above-described conventional second original cover closer is of a cantilevered type, the original cover tends to swing to the right and the left during the opening and closing operation and thereby has poor stability.